Control and method of control for an earth moving system

• US 20080073089A1
• Filed: 09/27/2006
• Published: 03/27/2008
• Est. Priority Date: 09/27/2006
• Status: Active Grant

• Current Assignee: Caterpillar Trimble Control Technologies LLC
• Original Assignee: Caterpillar Trimble Control Technologies LLC
• Inventors: Green, Francisco
• Granted Patent: US 7,970,519 B2
• Time in Patent Office: Days
• US Class Current: 172/2
• CPC Class Codes: E02F 3/847 using electromagnetic, optical or acoustic beams to determine the blade position, e.g. laser beams
• CPC Class Codes: E02F 9/2037 Coordinating the movements of the implement and of the frame
• CPC Class Codes: G05D 1/0891 specially adapted for land vehicles

Abstract

An earthmoving system, includes in one embodiment a laser transmitter for transmitting a reference beam of laser light, and a laser receiver mounted on a mast on the bulldozer blade. The bulldozer has a frame and a cutting blade supported by a blade support extending from said frame. The blade support includes hydraulic cylinders for raising and lowering the blade in relation to said frame, and for tilting the blade along its length. The mast extends upward from, and is movable with, the blade. An inclinometer is mounted for movement with the blade to provide an indication of the inclination of the blade. A sensor detects turning of the bulldozer. A control is responsive to the laser receiver, to the inclinometer, and to the sensor, for controlling the operation of said cylinders and adjusting the position of said blade. When rapid turning of said bulldozer is detected the control operates to reduce the errors that would otherwise result from an erroneous inclinometer output.

Claims

1. An earthmoving system, comprising:

a laser transmitter for transmitting a reference beam of laser light,

a bulldozer, having a frame and a cutting blade supported by a blade support extending from said frame, said blade support including hydraulic cylinders for raising and lowering said blade in relation to said frame,

a laser receiver mounted on a mast extending upward from, and movable with, said cutting blade, said laser receiver sensing said reference beam of laser light,

an inclinometer mounted for movement with said cutting blade to provide an indication of the inclination of said blade,

a sensor for detecting turning of said bulldozer, and

a control, responsive to said laser receiver, to said inclinometer, and to said sensor, for controlling the operation of said cylinders and adjusting the position of said blade, said control keeping said blade at an unchanged level when rapid turning of said bulldozer is detected, whereby erroneous vertical movement of the blade is reduced.

2. The earthmoving system of claim 1, in which said laser transmitter comprises a transmitter that provides a rotating beam of laser light, and in which said control determines the position of said cutting blade each time said receiver is illuminated by said rotating beam.

3. The earthmoving system of claim 1, in which said sensor comprises a sensor connected to the steering system of said bulldozer to detect turning.

4. The earthmoving system of claim 1, in which said sensor comprises a circuit for detecting a rapid change in the output of said inclinometer without an operation of the hydraulic cylinders that would account for such a change.

5. The earthmoving system of claim 1, in which said sensor comprises a circuit for detecting a rapid change in the output of said inclinometer.

6. The earthmoving system of claim 1, in which said control keeps said blade at an unchanged level for a preset period of time after turning of said bulldozer is discontinued, whereby erroneous vertical movement of the blade is reduced.

7. An earthmoving system, comprising:

an earthmoving machine, having a cutting blade supported by a blade support, said blade support including hydraulic cylinders for raising and lowering said blade in relation to said frame,

a laser receiver mounted on a mast extending upward from, and movable with, said cutting blade, said laser receiver sensing a reference beam of laser light,

an inclinometer mounted for movement with said cutting blade to provide an indication of the inclination of said blade,

a sensor for detecting turning of said machine, and

a control, responsive to said laser receiver, to said inclinometer, and to said sensor, for controlling the operation of said cylinders and adjusting the position of said blade, said control keeping said blade at an unchanged level when rapid turning of said machine is detected, whereby erroneous vertical movement of the blade is reduced.

8. The earthmoving system of claim 7, in which said sensor comprises a sensor connected to the steering system of said earthmoving machine to detect turning.

9. The earthmoving system of claim 7, in which said sensor comprises a circuit for detecting a rapid change in the output of said inclinometer without an operation of the hydraulic cylinders that would account for such a change.

10. The earthmoving system of claim 7, in which said sensor comprises a circuit for detecting a rapid change in the output of said inclinometer.

11. The earthmoving system of claim 7, in which said control keeps said blade at an unchanged level for a preset period of time after turning of said earthmoving machine is discontinued, whereby erroneous vertical movement of the blade is reduced.

12. A method of controlling the position of the cutting blade of a bulldozer, said bulldozer having a frame and said cutting blade, said cutting blade supported by a blade support extending from said frame, said blade support including hydraulic cylinders for raising and lowering said blade in relation to said frame, comprising the steps of:

periodically determining the location of the cutting blade by sensing the relative position of a reference beam of laser light using a laser receiver mounted on a mast extending upward from said cutting blade,

sensing the inclination of the cutting blade with an inclinometer mounted on said blade,

sensing turning of said bulldozer, and

controlling the operation of said cylinders and thereby the position of said cutting blade such that the vertical position of the cutting blade is not changed for a period of time during turning of the bulldozer.

13. The method of controlling the position of the cutting blade of a bulldozer according to claim 12, in which the sensor is connected to the steering system of said bulldozer to detect turning.

14. The method of controlling the position of the cutting blade of a bulldozer according to claim 12, in which the sensor includes a circuit for detecting a rapid change in the output of the inclinometer without an operation of the hydraulic cylinders that would account for such a change.

15. The method of controlling the position of the cutting blade of a bulldozer according to claim 12, in which said sensor detects a rapid change in the output of said inclinometer.

16. The method of controlling the position of the cutting blade of a bulldozer according to claim 12, in which said control maintains said blade at an unchanged level for a preset period of time after turning said bulldozer is discontinued, whereby erroneous vertical movement of the blade is reduced.

17. An earthmoving system, comprising:

a bulldozer, having a cutting blade supported by a blade support extending from said frame, said blade support including hydraulic cylinders for raising and lowering said blade in relation to said frame,

a reference position system for determining the position of the bulldozer,

an inclinometer mounted for movement with said cutting blade to provide an indication of the inclination of said blade,

a sensor for detecting turning of said bulldozer, and

a control, responsive to said inclinometer and to said sensor, for controlling the operation of said cylinders and adjusting the position of said blade, said control keeping said blade at an unchanged level when rapid turning of said bulldozer is detected, whereby erroneous vertical movement of the blade is reduced.

18. The earthmoving system of claim 17, in which said sensor comprises a sensor connected to the steering system of said bulldozer to detect turning.

19. The earthmoving system of claim 17, in which said sensor comprises a circuit for detecting a rapid change in the output of said inclinometer without an operation of the hydraulic cylinders that would account for such a change.

20. The earthmoving system of claim 17, in which said sensor comprises a circuit for detecting a rapid change in the output of said inclinometer.

21. The earthmoving system of claim 17, in which said control keeps said blade at an unchanged level for a preset period of time after turning of said bulldozer is discontinued, whereby erroneous vertical movement of the blade is reduced.

22. A method of controlling the position of the cutting blade of a bulldozer, supported by a blade support including hydraulic cylinders for raising and lowering said blade, said bulldozer further including an inclinometer providing an indication of the inclination of the blade, comprising the steps of:

operating said cylinders to controlling the height and inclination of the cutting blade in response to outputs from the said inclinometer,

sensing turning of said bulldozer, and

maintaining the position of the cylinders when turning of the bulldozer is sensed, regardless of the output from the inclinometer, for a period sufficient to avoid undesired fluctuation in the height of the cutting blade.

23. An earthmoving system, comprising:

a bulldozer, having a frame and a cutting blade supported by a blade support extending from said frame, said blade support including hydraulic cylinders for raising and lowering said blade in relation to said frame, and changing the inclination of said blade along its length,

a position sensor mounted on a mast extending upward from, and movable with, said cutting blade, said position sensor sensing its vertical position,

an inclinometer mounted for movement with said cutting blade to provide an indication of the inclination of said blade,

a turning sensor for detecting turning of said bulldozer, and

a control, responsive to said position sensor, to said inclinometer, and to said turning sensor, for controlling the operation of said cylinders and adjusting the position and inclination of said blade, said preventing operation of said cylinders when rapid turning of said bulldozer is detected, whereby erroneous vertical movement and erroneous tilting of the blade are reduced.

24. The earthmoving system of claim 23, further comprising a laser transmitter for transmitting a reference beam of laser light, and in which said position sensor comprises a laser receiver sensing said reference beam of laser light.

25. The earthmoving system of claim 23, in which said position sensor comprises a GPS receiver having a GPS antenna mounted on said mast.

26. An earthmoving system, comprising:

a bulldozer, having a frame and a cutting blade supported by a blade support extending from said frame, said blade support including hydraulic cylinders for raising and lowering said blade in relation to said frame, and changing the inclination of said blade along its length,

a position sensor mounted on a mast extending upward from, and movable with, said cutting blade, said position sensor sensing its vertical position,

an inclinometer mounted for movement with said cutting blade to provide an indication of the inclination of said blade,

a turning sensor for detecting turning of said bulldozer, and

a control, responsive to said position sensor, to said inclinometer, and to said turning sensor, for controlling the operation of said cylinders and adjusting the position and inclination of said blade, such that errors from the erroneous output from said inclinometer during turning of said bulldozer are minimized.

27. The earthmoving system of claim 26, in which said turning sensor for detecting turning of said bulldozer comprises a sensor monitoring movement of the steering mechanism of said bulldozer.

28. The earthmoving system of claim 26, in which said turning sensor for detecting turning of said bulldozer comprises an inertia guidance system.

29. The earthmoving system of claim 26, in which said turning sensor for detecting turning of said bulldozer comprises a circuit which monitors the output of said inclinometer and interprets a rapid change of such output as caused by turning.

30. The earthmoving system of claim 26, in which said control keeps said inclination of said blade at an unchanged level when rapid turning of said bulldozer is detected, and permits the height of said blade to be controlled in dependence upon the output of said position sensor during turning and upon the output of said inclinometer immediately prior to turning.

31. An earthmoving system, comprising:

a bulldozer, having a frame and a cutting blade supported by a blade support extending from said frame, said blade support including a hydraulic cylinder for changing the inclination of said blade along its length,

an inclinometer mounted for movement with said cutting blade to provide an indication of the inclination of said blade,

a sensor for detecting turning of said bulldozer, and

a control, responsive to said inclinometer, for controlling the operation of said cylinder and adjusting the inclination of said blade, said control keeping said blade at an unchanged inclination when rapid turning of said bulldozer is detected, whereby erroneous vertical movement and erroneous tilting of the blade are reduced.

32. A method of controlling the position of the cutting blade of a bulldozer, said bulldozer having a frame and said cutting blade, said cutting blade supported by a blade support extending from said frame, said blade support including hydraulic cylinders for raising and lowering said blade in relation to said frame, and for tilting said blade, comprising the steps of:

periodically determining the location of a sensor mounted on a mast extending upward from said cutting blade,

sensing the inclination of the cutting blade and the mast with an inclinometer mounted on said blade,

sensing turning of said bulldozer, and

controlling the operation of said cylinders and thereby the position of said cutting blade during turning of the bulldozer such that the height of the blade is not affected by an erroneous output from said inclinometer.

33. The method of controlling the position of the cutting blade of a bulldozer according to claim 32, in which the height of said blade is sensed with a laser receiver mounted on said mast.

34. The method of controlling the position of the cutting blade of a bulldozer according to claim 32, in which the height of said blade is sensed with a GPS receiver having an antenna mounted on said mast.

35. The method of controlling the position of the cutting blade of a bulldozer according to claim 32, in which turning of said bulldozer is sensed by monitoring the steering of said bulldozer.

36. The method of controlling the position of the cutting blade of a bulldozer according to claim 32, in which turning of said bulldozer is sensed by use of an inertial sensor.

37. The method of controlling the position of the cutting blade of a bulldozer according to claim 32, in which turning of said bulldozer is sensed by a rapid change in the output of said inclinometer.

38. The method of controlling the position of the cutting blade of a bulldozer according to claim 32, in which the step of controlling the operation of said cylinders and thereby the position of said cutting blade during turning of the bulldozer such that the height of the blade is not affected by an erroneous output from said inclinometer includes the step of keeping said blade at an unchanged level for a preset period of time after turning of said bulldozer is discontinued, whereby erroneous vertical movement of the blade is reduced.

39. The method of controlling the position of the cutting blade of a bulldozer according to claim 32, in which the step of controlling the operation of said cylinders and thereby the position of said cutting blade during turning of the bulldozer such that the height of the blade is not affected by an erroneous output from said inclinometer includes the step of maintaining the height of the blade at its then current height when turning of the bulldozer is sensed, regardless of the output from the inclinometer, for a period sufficient to avoid undesired fluctuation in the height of the cutting blade.

40. The method of controlling the position of the cutting blade of a bulldozer according to claim 32, in which the step of controlling the operation of said cylinders and thereby the position of said cutting blade during turning of the bulldozer such that the height of the blade is not affected by an erroneous output from said inclinometer includes the step of using the output of the inclinometer which was sensed prior to the initiation of turning in determining the height of the blade during turning.

41. The method of controlling the position of the cutting blade of a bulldozer according to claim 32, in which the inclination of the blade is not changed during the turning of the bulldozer.